Research On Criminal Scientific Evidence

Criminal scientific evidence is a double-edged sword. On the one hand, it plays a part in the identification of the facts and the detection of the case; on the other hand, it leads to wrong cases if improperly used. Judging from both the substantive and procedural perspectives, this paper mainly discusses the application of criminal scientific evidence to the judicial practice in our country, and attempts to make a research on some problems in these two aspects, in order to make full use of criminal scientific evidence in our country.On the classification of criminal scientific evidence, opinions of domestic and foreign scholars are divergent. Some scholars classify it from a practical perspective, dividing it into certain types by specific enumeration; but some scholars classify it from a theoretical perspective, sorting it with a definition by particular description. In this paper, criminal scientific evidence and legal evidences provided in "Code of Criminal Procedure" compatibly cross each other. Criminal scientific evidence chiefly includes expert conclusions and audio-visual materials; meanwhile, some criminal scientific evidence belongs to the physical evidence and documentary evidence.From a substantive perspective, the substantive standard of criminal scientific evidence is how "scientific" should the scientific evidence be to enter into the criminal court. On the substantive standard of criminal scientific evidence, the United States focuses on the construction of expert witness system, rather concerned about the reliability of expert testimony, whose rule evolves from the "Frye" Rule established in "Frye v. United States" case in 1923 to the "Daubert" Rule established in "Daubert v. Merrell Dow Pharmaceuticals. Inc." case in 1993, and the "Ultimate Issue Rule". On the other words, at present, the substantive standards of criminal scientific evidence in the U.S. are mainly the "Daubert" Rule and "Ultimate Issue Rule". Based on reliable principles and methods, experts can testify the facts of a case if they have sufficient information or figures; but the competency and the corroboration of these scientific evidences depend on the judges'or the jury's discretion. When judges or a jury consider such a question, they should consider whether the theory and the methods relied on by scientific evidence can be tested, repeated, believed and with few errors.From a procedural perspective, the procedural rules of criminal scientific evidence is how "legal" should the scientific evidence be in the collection, preservation, identification and examination. At first, in the collection phase, two issues should be noticed:first, the integrity of criminal scientific evidence-- the types of collected criminal scientific evidence should be comprehensive and detailed; and second, the legitimacy of criminal scientific evidence--the means of gathering criminal scientific evidence should be legal and valid. In the preservation phase, four issues should be noticed:first, to select appropriate containers to preserve criminal scientific evidence; second, to pack criminal scientific evidence separately; third, to use clean containers; and fourth, to establish a registration system for evidence. In the identification phase, two issues should be noticed:the qualification of the identifier and the management of the authentication institutions. Finally, in the examination phase, three requirements must be followed:first, to provide the obligation of the identifier attending in court; second, to entitle the accused to engage their own identifier; and third, to give guidance to the judges on exercising fully their discretion.